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Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study
l-theanine (γ-glutamylethylamide), an amino acid in green tea, has been shown to affect brain functions by relieving stress disorders, improving mood, and maintaining normal sleep. However, the cognitive functions for which theanine is effective are unclear. This study aimed to clarify which cogniti...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Mary Ann Liebert, Inc., publishers
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8080935/ https://www.ncbi.nlm.nih.gov/pubmed/33751906 http://dx.doi.org/10.1089/jmf.2020.4803 |
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author | Baba, Yoshitake Inagaki, Shun Nakagawa, Sae Kaneko, Toshiyuki Kobayashi, Makoto Takihara, Takanobu |
author_facet | Baba, Yoshitake Inagaki, Shun Nakagawa, Sae Kaneko, Toshiyuki Kobayashi, Makoto Takihara, Takanobu |
author_sort | Baba, Yoshitake |
collection | PubMed |
description | l-theanine (γ-glutamylethylamide), an amino acid in green tea, has been shown to affect brain functions by relieving stress disorders, improving mood, and maintaining normal sleep. However, the cognitive functions for which theanine is effective are unclear. This study aimed to clarify which cognitive functions are positively affected by intake of l-theanine. A double-blind, randomized, placebo-controlled study was conducted. The subjects were Japanese men and women aged 50–69 years. Mini Mental State Examination-Japanese version score was 24 or higher. Cognitrax was used as a test battery for cognitive function. Evaluations were performed before the intervention, after a single dose of l-theanine, and after 12 weeks of regular intake. The single dose of l-theanine reduced the reaction time to attention tasks (Stroop test, Part 1), and it increased the number of correct answers and decreased the number of omission errors in working memory tasks (4-Part continuous performance test, Part 4). In conclusion, our study indicated that l-theanine may contribute to improving attention, thus enhancing working memory and executive functions. Clinical Trial No.: UMIN000033812. |
format | Online Article Text |
id | pubmed-8080935 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Mary Ann Liebert, Inc., publishers |
record_format | MEDLINE/PubMed |
spelling | pubmed-80809352021-04-29 Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study Baba, Yoshitake Inagaki, Shun Nakagawa, Sae Kaneko, Toshiyuki Kobayashi, Makoto Takihara, Takanobu J Med Food Full Communications l-theanine (γ-glutamylethylamide), an amino acid in green tea, has been shown to affect brain functions by relieving stress disorders, improving mood, and maintaining normal sleep. However, the cognitive functions for which theanine is effective are unclear. This study aimed to clarify which cognitive functions are positively affected by intake of l-theanine. A double-blind, randomized, placebo-controlled study was conducted. The subjects were Japanese men and women aged 50–69 years. Mini Mental State Examination-Japanese version score was 24 or higher. Cognitrax was used as a test battery for cognitive function. Evaluations were performed before the intervention, after a single dose of l-theanine, and after 12 weeks of regular intake. The single dose of l-theanine reduced the reaction time to attention tasks (Stroop test, Part 1), and it increased the number of correct answers and decreased the number of omission errors in working memory tasks (4-Part continuous performance test, Part 4). In conclusion, our study indicated that l-theanine may contribute to improving attention, thus enhancing working memory and executive functions. Clinical Trial No.: UMIN000033812. Mary Ann Liebert, Inc., publishers 2021-04-01 2021-04-16 /pmc/articles/PMC8080935/ /pubmed/33751906 http://dx.doi.org/10.1089/jmf.2020.4803 Text en © Yoshitake Baba, et al., 2021; Published by Mary Ann Liebert, Inc. https://creativecommons.org/licenses/by-nc/4.0/This Open Access article is distributed under the terms of the Creative Commons Attribution Noncommercial License [CC-BY-NC] (http://creativecommons.org/licenses/by-nc/4.0/ (https://creativecommons.org/licenses/by-nc/4.0/) ) which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author(s) and the source are cited. |
spellingShingle | Full Communications Baba, Yoshitake Inagaki, Shun Nakagawa, Sae Kaneko, Toshiyuki Kobayashi, Makoto Takihara, Takanobu Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study |
title | Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study |
title_full | Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study |
title_fullStr | Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study |
title_full_unstemmed | Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study |
title_short | Effects of l-Theanine on Cognitive Function in Middle-Aged and Older Subjects: A Randomized Placebo-Controlled Study |
title_sort | effects of l-theanine on cognitive function in middle-aged and older subjects: a randomized placebo-controlled study |
topic | Full Communications |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8080935/ https://www.ncbi.nlm.nih.gov/pubmed/33751906 http://dx.doi.org/10.1089/jmf.2020.4803 |
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